Liam Cosgrave, 97, a dour and dogged former prime minister of Ireland whose ingrained devotion to political stability in the 1970s helped break his country’s cycle of violence, died Wednesday in Dublin.

Cosgrave’s law-and-order agenda and renunciation of terror were steeped in his family’s protracted revolt against British domination since the Irish Rebellion of 1798.

His father, W.T. Cosgrave, participated in the 1916 Easter Rising and was sentenced to death for his role in it, though the sentence was later commuted to a life term, which in turn was nullified when he was released in 1917.

Liam Cosgrave was a member of the Dail Eireann, or Assembly of Ireland, from 1943, when he was 23, until 1981 and led the Fine Gael party from 1965 to 1977. He was elected prime minister in 1973, but an economic slump helped doom his chances for re-election four years later.

During his one term in office, he negotiated what became known as the Sunningdale Agreement, which diluted the Irish Republic’s constitutional claim to Northern Ireland. The agreement signed by the mostly Roman Catholic republic acknowledged that the predominantly Protestant north was a province under British control.

Both sides agreed that the status of the six counties that constituted Northern Ireland could change, but only by a majority vote of their residents.

While the agreement collapsed within months, it formed the basis for the 1998 Good Friday power-sharing arrangement that eventually ended years of sectarian violence in Northern Ireland, commonly known as the Troubles. Seamus Mallon, a Northern Irish minister, described the Good Friday Agreement as “Sunningdale for slow learners.”

Liam Cosgrave was born on April 13, 1920, in Castleknock, a Dublin suburb.